Final answer:
The book in question is not clearly identified in the provided information. The passages given discuss various writers and works, but do not match the specific plot detail of co-writing an article about a cousin.
Step-by-step explanation:
The book in which the main character wants to co-write an article about his cousin with his new friend is not clearly stated among the provided information. However, the descriptions and selected key sentences provided don’t seem to include a story that matches the specific plot detail mentioned in the question. The passages instead offer insights into various writers and their works, experiences, and subjects ranging from online writer communities to historical fiction and the Civil Rights movement. To accurately identify the book in question, one would typically look for a novel featuring characters involved in a cooperative writing endeavor about a family member, likely within a contemporary setting where such an activity would be plausible.